Tertiary amines are an important intermediate material in domestic and industrial application fields, and have been extensively used in various applications such as fabric softeners, shampoos, rinses, antistatic agents, detergents, dispersants, textile auxiliaries, etc.
There are known various processes for production of the tertiary amines. In one of these processes, an alcohol and an amine are contacted with each other in the presence of hydrogen and a catalyst. As the catalyst used in the above process, there are known transition metal catalysts such as copper-based catalysts (refer to Patent Document 1) and nickel-based catalysts (refer to Patent Document 2), noble metal catalysts such as ruthenium-based catalysts (refer to Patent Document 3) or the like.
In the production process using the above catalysts, the tertiary amines are produced through the following three steps (a) to (c).
Step (a): subjecting a raw alcohol to dehydrogenation reaction to produce an aldehyde;
Step (b): subjecting the thus produced aldehyde to nucleophilic addition reaction with an amine and then subjecting the obtained reaction product to dehydration reaction to produce an enamine; and
Step (c): subjecting the thus produced enamine to hydrogenation reaction to produce the tertiary amine.
In the above production process, it is required that a large amount of a hydrogen gas is used as a substrate for the hydrogenation reaction or as a carrier gas for driving water produced in the reaction out of the reaction system, and further for the purposes of enhancing a reactivity and a selectivity and improving an appearance of the obtained reaction product or a coloring property when forming a derivative thereof.    Patent Document 1; JP 2-233A    Patent Document 2: JP 50-30804A    Patent Document 3; JP 8-243392A